Since the 1950s, polymeric materials have been integrated into cementitious matrices to improve their properties and durability, replacing steel or asbestos fibers. The effectiveness of these fibers depends on factors such as matrix properties, fiber type, volume, and dispersion. Recent advances in electrospinning techniques allow the production of polymeric nanofibers with distinct structural characteristics, making them suitable for various applications, including construction. This study investigates the effects of electrospun PET and PVB fibers as additives in mortar composites. The fibers, produced and characterized by SEM and thermogravimetric analysis, were incorporated into the mortar in varying concentrations. The fresh and hardened states of the composites were evaluated for consistency, mass density, incorporated air, water absorption, capillarity coefficient, and mechanical resistance. The results indicate that the addition of fibers increases matrix densification by up 5%, reduces water absorption by up 36% and improves mechanical properties. It was also found that additions of 0.125% PET and 0.250% PVB exhibited significant improvements in compressive and flexural strength, approximately 8 and 29%, respectively. The study concludes that electrospun polymer fibers can contribute to more durable and mechanically resilient cementitious composites, with potential implications for their wider application in the construction industry.